What is Hypnosis?

Hypnosis is a mental state (state theory) or set of attitudes (nonstate theory) usually induced by a procedure known as a hypnotic induction, which is commonly composed of a series of preliminary instructions and suggestions. Hypnotic suggestions may be delivered by a hypnotist in the presence of the subject (‘hetero-suggestion’), or may be self-administered (‘self-suggestion’ or ‘autosuggestion’). The use of hypnotism for therapeutic purposes is referred to as hypnotherapy“.

The words ‘hypnosis’ and ‘hypnotism’ both derive from the term ‘neuro-hypnotism’ (nervous sleep) coined by the Scottish physician and surgeon James Braid around 1841 to distinguish his theory and practice from those developed by Franz Anton Mesmer and his followers (‘Mesmerism‘ or ‘animal magnetism‘).

Although a popular misconception is that hypnosis is a form of unconsciousness resembling sleep, contemporary research suggests that it is actually a wakeful state of focused attention and heightened suggestibility, with diminished peripheral awareness. In the first book on the subject, Neurypnology (1843), Braid described ‘hypnotism’ as a state of physical relaxation (‘nervous sleep’) accompanied and induced by mental concentration (‘abstraction’).

Sceptics point out the difficulty distinguishing between hypnosis and the placebo effect, proposing that the state called hypnosis is.,

“So heavily reliant upon the effects of suggestion and belief that it would be hard to imagine how a credible placebo control could ever be devised for a hypnotism study.”

However, hypnotism itself originated out of very early placebo controlled experiments, conducted by Braid and others. Many researchers and clinicians would therefore object that hypnotic suggestion is explicitly intended to make use of the placebo effect, e.g., Irving Kirsch has proposed a definition of hypnosis as a ‘non-deceptive mega-placebo’, i.e., a method which openly makes use of suggestion and employs methods to amplify its effects. It is therefore surprisingly difficult to distinguish between the views of skeptics and proponents regarding hypnotism.

Definitions

The earliest definition of hypnosis was given by Braid, who coined the term ‘hypnotism’ as an abbreviation for ‘neuro-hypnotism’, or nervous sleep, which he opposed to normal sleep, and defined as.,

“A peculiar condition of the nervous system, induced by a fixed and abstracted attention of the mental and visual eye, on one object, not of an exciting nature.”

Braid elaborated upon this brief definition in a later work.,

“The real origin and essence of the hypnotic condition, is the induction of a habit of abstraction or mental concentration, in which, as in reverie or spontaneous abstraction, the powers of the mind are so much engrossed with a single idea or train of thought, as, for the nonce, to render the individual unconscious of, or indifferently conscious to, all other ideas, impressions, or trains of thought. The hypnotic sleep, therefore, is the very antithesis or opposite mental and physical condition to that which precedes and accompanies common sleep.”

Braid therefore defined hypnotism as a state of mental concentration which often led to a form of progressive relaxation termed ‘nervous sleep’. Later, in his The Physiology of Fascination (1855), Braid conceded that his original terminology was misleading, and argued that the term ‘hypnotism’ or ‘nervous sleep’ should be reserved for the minority (10%) of subjects who exhibited amnesia, substituting the term ‘monoideism’, meaning concentration upon a single idea, as a description for the more alert state experienced by the others.

A modern account of hypnosis, derived from academic psychology, was provided in 2005, when the Society for Psychological Hypnosis, Division 30 of the American Psychological Association (APA), published the following formal definition.,

The American Psychological Association’s Definition of Hypnosis

“Hypnosis typically involves an introduction to the procedure during which the subject is told that suggestions for imaginative experiences will be presented. The hypnotic induction is an extended initial suggestion for using one’s imagination, and may contain further elaborations of the introduction. A hypnotic procedure is used to encourage and evaluate responses to suggestions.”

“When using hypnosis, one person (the subject) is guided by another (the hypnotist) to respond to suggestions for changes in subjective experience, alterations in perception, sensation, emotion, thought or behaviour. Persons can also learn self-hypnosis, which is the act of administering hypnotic procedures on one’s own. If the subject responds to hypnotic suggestions, it is generally inferred that hypnosis has been induced. Many believe that hypnotic responses and experiences are characteristic of a hypnotic state. While some think that it is not necessary to use the word ‘hypnosis’ as part of the hypnotic induction, others view it as essential.”

“Details of hypnotic procedures and suggestions will differ depending on the goals of the practitioner and the purposes of the clinical or research endeavour. Procedures traditionally involve suggestions to relax, though relaxation is not necessary for hypnosis and a wide variety of suggestions can be used including those to become more alert. Suggestions that permit the extent of hypnosis to be assessed by comparing responses to standardised scales can be used in both clinical and research settings. While the majority of individuals are responsive to at least some suggestions, scores on standardised scales range from high to negligible.”

Induction

Hypnosis is normally preceded by a ‘hypnotic induction’ technique. Traditionally this was interpreted as a method of putting the subject into a ‘hypnotic trance’; however subsequent ‘nonstate’ theorists have viewed it differently, as a means of heightening client expectation, defining their role, focusing attention, etc.

There are an enormous variety of different induction techniques used in hypnotism. However, by far the most influential method was the original ‘eye-fixation’ technique of Braid, also known as ‘Braidism’. Many variations of the eye-fixation approach exist, including the induction used in the Stanford Hypnotic Susceptibility Scale (SHSS), the most widely-used research tool in the field of hypnotism. Braid’s original description of his induction is as follows.,

James Braid’s Original Eye-Fixation Hypnotic Induction Method

“Take any bright object (I generally use my lancet case) between the thumb and fore and middle fingers of the left hand; hold it from about eight to fifteen inches from the eyes, at such position above the forehead as may be necessary to produce the greatest possible strain upon the eyes and eyelids, and enable the patient to maintain a steady fixed stare at the object.”

“The patient must be made to understand that he is to keep the eyes steadily fixed on the object, and the mind riveted on the idea of that one object. It will be observed, that owing to the consensual adjustment of the eyes, the pupils will be at first contracted: they will shortly begin to dilate, and after they have done so to a considerable extent, and have assumed a wavy motion, if the fore and middle fingers of the right hand, extended and a little separated, are carried from the object towards the eyes, most probably the eyelids will close involuntarily, with a vibratory motion.”

“If this is not the case, or the patient allows the eyeballs to move, desire him to begin anew, giving him to understand that he is to allow the eyelids to close when the fingers are again carried towards the eyes, but that the eyeballs must be kept fixed, in the same position, and the mind riveted to the one idea of the object held above the eyes. It will generally be found, that the eyelids close with a vibratory motion, or become spasmodically closed.”

Braid himself later acknowledged that the hypnotic induction technique was not necessary in every case and subsequent researchers have generally found that on average it contributes less than previously expected to the effect of hypnotic suggestions (q.v., Barber, Spanos & Chaves, 1974). Many variations and alternatives to the original hypnotic induction techniques were subsequently developed. However, exactly 100 years after Braid introduced the method, another expert could still state: “It can be safely stated that nine out of ten hypnotic techniques call for reclining posture, muscular relaxation, and optical fixation followed by eye closure.”

Suggestion

When Braid first introduced hypnotism, he did not use the term ‘suggestion‘ but referred instead to the act of focusing the conscious mind of the subject upon a single dominant idea. Braid’s main therapeutic strategy involved stimulating or reducing physiological functioning in different regions of the body. In his later works, however, Braid placed increasing emphasis upon the use of a variety of different verbal and non-verbal forms of suggestion, including the use of ‘waking suggestion’ and self-hypnosis. Subsequently, Hippolyte Bernheim shifted the emphasis from the physical state of hypnosis on to the psychological process of verbal suggestion.

“I define hypnotism as the induction of a peculiar psychical [i.e., mental] condition which increases the susceptibility to suggestion. Often, it is true, the [hypnotic] sleep that may be induced facilitates suggestion, but it is not the necessary preliminary. It is suggestion that rules hypnotism.” (Hypnosis & Suggestion, 1884: 15)

Bernheim’s conception of the primacy of verbal suggestion in hypnotism dominated the subject throughout the twentieth century, leading some authorities to declare him the father of modern hypnotism (Weitzenhoffer, 2000). Contemporary hypnotism makes use of a wide variety of different forms of suggestion including: direct verbal suggestions, ‘indirect’ verbal suggestions such as requests or insinuations, metaphors and other rhetorical figures of speech, and non-verbal suggestion in the form of mental imagery, voice tonality, and physical manipulation. A distinction is commonly made between suggestions delivered ‘permissively’ or in a more ‘authoritarian’ manner.

Some hypnotic suggestions are intended to bring about immediate responses, whereas others (post-hypnotic suggestions) are intended to trigger responses after a delay ranging from a few minutes to many years in some reported cases.

Consciousness vs. unconscious mind

Some hypnotists conceive of suggestions as being a form of communication directed primarily to the subject’s conscious mind, whereas others view suggestion as a means of communicating with the ‘unconscious’ or ‘subconscious’ mind. These concepts were introduced into hypnotism at the end of 19th century by Sigmund Freud and Pierre Janet. The original Victorian pioneers of hypnotism, including Braid and Bernheim, did not employ these concepts but considered hypnotic suggestions to be addressed to the subject’s conscious mind. Indeed, Braid actually defines hypnotism as focused (conscious) attention upon a dominant idea (or suggestion). Different views regarding the nature of the mind have led to different conceptions of suggestion. Hypnotists who believed that responses are mediated primarily by an ‘unconscious mind’, like Milton Erickson, made more use of indirect suggestions, such as metaphors or stories, whose intended meaning may be concealed from the subject’s conscious mind. The concept of subliminal suggestion also depends upon this view of the mind. By contrast, hypnotists who believed that responses to suggestion are primarily mediated by the conscious mind, such as Theodore Barber and Nicholas Spanos tended to make more use of direct verbal suggestions and instructions.

Ideo-dynamic reflex

The first neuro-psychological theory of hypnotic suggestion was introduced early on by James Braid who adopted his friend and colleague William Carpenter’s theory of the ideo-motor reflex response to account for the phenomena of hypnotism. Carpenter had observed from close examination of everyday experience that under certain circumstances the mere idea of a muscular movement could be sufficient to produce a reflexive, or automatic, contraction or movement of the muscles involved, albeit in a very small degree. Braid extended Carpenter’s theory to encompass the observation that a wide variety of bodily responses, other than muscular movement, can be thus affected, e.g., the idea of sucking a lemon can automatically stimulate salivation, a secretory response. Braid therefore adopted the term ‘ideo-dynamic’, meaning ‘by the power of an idea’ to explain a broad range of ‘psycho-physiological’ (mind-body) phenomena. Braid coined the term ‘mono-ideodynamic’ to refer to the theory that hypnotism operates by concentrating attention on a single idea in order to amplify the ideo-dynamic reflex response. Variations of the basic ideo-motor or ideo-dynamic theory of suggestion have continued to hold considerable influence over subsequent theories of hypnosis, including those of Clark L. Hull, Hans Eysenck, and Ernest Rossi. It should be noted that in Victorian psychology, the word ‘idea’ encompasses any mental representation, e.g., including mental imagery, or memories, etc.

Post-hypnotic suggestion

Post-hypnotic suggestion can be used to change people’s behaviour after emerging from hypnosis. One author wrote that “a person can act, some time later, on a suggestion seeded during the hypnotic session. For example, a hypnotherapist told one of his patients (who was also a friend) that when he touched them on the finger they would immediately be hypnotised. Fourteen years later, whilst at a dinner party, the hypnotherapist touched this same friend deliberately on the finger and his head fell back against the chair.”

Susceptibility

Main article: Hypnotic susceptibility. Braid made a rough distinction between different stages of hypnosis which he termed the first and second conscious stage of hypnotism, he later replaced this with a distinction between ‘sub-hypnotic’, ‘full hypnotic’, and ‘hypnotic coma’ stages. Jean-Martin Charcot made a similar distinction between stages named somnambulism, lethargy, and catalepsy. However, Ambroise-Auguste Liébeault and Bernheim introduced more complex hypnotic ‘depth’ scales, based on a combination of behavioural, physiological and subjective responses, some of which were due to direct suggestion and some of which were not. In the first few decades of the 20th century, these early clinical ‘depth’ scales were superseded by more sophisticated ‘hypnotic susceptibility’ scales based on experimental research. The most influential were the Davis-Husband and Friedlander-Sarbin scales developed in the 1930s. André Weitzenhoffer and Ernest R. Hilgard developed the Stanford Scale of Hypnotic Susceptibility in 1959, consisting of 12 suggestion test items following a standardised hypnotic eye-fixation induction script, and this has become one of the most widely-referenced research tools in the field of hypnosis. Soon after, in 1962, Ronald Shor and Emily Carota Orne developed a similar group scale called the Harvard Group Scale of Hypnotic Susceptibility (HGSHS).

Whereas the older ‘depth scales’ tried to infer the level of ‘hypnotic trance’ based upon supposed observable signs, such as spontaneous amnesia, most subsequent scales measure the degree of observed or self-evaluated responsiveness to specific suggestion tests, such as direct suggestions of arm rigidity (catalepsy).

Hypnotherapy

Hypnosis has been studied in many clinical situations with varying degrees of success. It has been used as a painkiller, an adjunct to weight loss, a treatment of skin disease, and a way to soothe anxious surgical patients. It has also been used as part of psychological therapy, a method of habit control, a way to relax, and a tool to enhance sports performance.

Self-hypnosis is popularly used by people who want to quit smoking and reduce stress, while stage hypnosis can be used to persuade people to perform unusual public feats.

Medical applications

Hypnotherapy has been successfully used as a treatment for irritable bowel syndrome, a pair of researchers who recently reviewed the best studies in this area, conclude.,

“The evidence for hypnosis as an efficacious treatment of IBS was encouraging. Two of three studies that investigated the use of hypnosis for IBS were well designed and showed a clear effect for the hypnotic treatment of IBS.”

A large number of clinical studies show that hypnosis can reduce the pain experienced by people undergoing burn-wound debridement, bone marrow aspirations, and childbirth. The International Journal of Clinical and Experimental Hypnosis found that hypnosis relieved the pain of 75% of 933 subjects participating in 27 different experiments.

In 1996, the National Institutes of Health declared hypnosis effective in reducing pain from cancer and other chronic conditions. Nausea and other symptoms related to incurable diseases may also be controlled with hypnosis. For example, research done at the Mt. Sinai School of Medicine studied two groups of patients facing surgery for breast cancer. The group that received hypnosis reported less pain, nausea, and anxiety post-surgery. There was a cost benefit as well: the average hypnosis patient reduced the cost of treatment by an average of £400.00 to £600.00 ($772.00).

Hypnodermatology is the practice of treating skin diseases with hypnosis: this therapy has performed well in studies treating warts, psoriasis, and atopic dermatitis.

Hypnosis may be useful as an adjunct therapy for weight loss. A 1996 meta-analysis studying the effectiveness of hypnosis combined with cognitive-behavioural therapy found that people using both treatments lost more weight than people using CBT alone.

Psychotherapy

Hypnotherapy is the use of hypnosis in psychotherapy. It is used by licensed physicians, psychologists, and in stand-alone environments. Physicians and psychiatrists may use hypnosis to help treat depression, anxiety, eating disorders, sleep disorders, compulsive gaming, and post-traumatic stress disorder.

Certified hypnotherapists who are not physicians or psychologists often do treatments for smoking cessation and weight loss. (Success rates vary: a meta-study researching hypnosis as a quit-smoking tool found it had a 20 to 30 percent success rate, similar to many other quit-smoking methods, while a 2007 study of patients hospitalised for cardiac and pulmonary ailments found that smokers who used hypnosis to quit smoking doubled their chances of success.

In a July 2001 article for Scientific American titled ‘The Truth and the Hype of Hypnosis’, Michael Nash wrote that “…using hypnosis, scientists have temporarily created hallucinations, compulsions, certain types of memory loss, false memories, and delusions in the laboratory so that these phenomena can be studied in a controlled environment.”

Controversy surrounds the use of hypnotherapy to retrieve memories, especially those from early childhood or (alleged) past-lives. The American Medical Association and the American Psychological Association have cautioned against the use of repressed memory therapy in cases of alleged childhood trauma, stating that “it is impossible, without other corroborative evidence, to distinguish a true memory from a false one.” Past Life Regression, meanwhile, is often viewed with scepticism.

Self-hypnosis

Self-hypnosis happens when a person hypnotises himself or herself, commonly involving the use of auto-suggestion. The technique is often used to increase motivation for a diet, quit smoking, or reduce stress. People who practice self-hypnosis sometimes require assistance; some people use devices known as mind machines to assist in the process, while others use hypnotic recordings.

Self-hypnosis is said to be a skill one can improve as time goes by, and can help reduce stage fright, promote relaxation, and enhance physical well-being.

Stage hypnosis

Stage hypnosis is a form of entertainment, traditionally employed in a club or theatre before an audience. Due to stage hypnotists’ showmanship, many people believe that hypnosis is a form of mind control. However, the effects of stage hypnosis are probably due to a combination of relatively ordinary social psychological factors such as peer pressure, social compliance, participant selection, ordinary suggestibility, and some amount of physical manipulation, stagecraft, and trickery. The desire to be the centre of attention, having an excuse to violate their own inner fear suppressors and the pressure to please are thought to convince subjects to ‘play along’. Books written by stage hypnotists sometimes explicitly describe the use of deception in their acts, for example, Ormond McGill’sNew Encyclopaedia of Stage Hypnosis describes an entire “fake hypnosis” act which depends upon the use of private whispers throughout.

[The hypnotist whispers off-microphone:] “We are going to have some good laughs on the audience and fool them… so when I tell you to do some funny things, do exactly as I secretly tell you.” (then deliberately wink at the spectator in a friendly fashion.)

Stage hypnosis traditionally employs three fundamental strategies.,

1. Participant compliance. Participants on stage tend to be compliant because of the social pressure felt in the situation constructed on stage, before an expectant audience.

2. Participant selection. Preliminary suggestion tests, such as asking the audience to clasp their hands and suggesting they cannot be separated, are usually used to select out the most suggestible and compliant subjects from the audience. By asking for volunteers to mount the stage, the performer also tends to select the most extroverted members of the audience.

3. Deception of the audience. Stage hypnotists are performers who traditionally, but not always, employ a variety of ‘sleight of hand’ strategies to mislead their audience for dramatic effect.

Some people have drawn analogies between certain aspects of hypnotism and areas such as crowd psychology, religious hysteria, and ritual trances in preliterate tribal cultures.

Theories

The State versus Nonstate Debate

The central theoretical disagreement in the history of hypnotism is known as the ‘state versus nonstate’ debate. When Braid introduced the concept of hypnotism he equivocated over the nature of the ‘state’, sometimes describing it as a specific sleep-like neurological state comparable to animal hibernation or yogic meditation, while at other times he emphasised that hypnotism encompassed a number of different stages or states which were essentially an extension of ordinary psychological and physiological processes. Overall, Braid appears to have moved from a more ‘special state’ understanding of hypnotism, at the start of his career, toward a more complex ‘nonstate’ orientation in his later works.

State theorists traditionally interpreted the effects of hypnotism as primarily due to a specific, abnormal and uniform psychological or physiological state of some description, often referred to as ‘hypnotic trance’ or an ‘altered state of consciousness’. Nonstate theorists rejected the idea of hypnotic trance and interpret the effects of hypnotism as due to a combination of multiple task-specific factors derived from normal cognitive, behavioural and social psychology, such as social role-perception and favourable motivation (Sarbin ), active imagination and positive cognitive set (Barber), response expectancy (Kirsch), and the active use of task-specific subjective strategies (Spanos). The personality psychologist Robert White is often cited as providing one of the first nonstate definitions of hypnosis in a 1941 article.,

“Hypnotic behaviour is meaningful, goal-directed striving, its most general goal being to behave like a hypnotised person as this is continuously defined by the operator and understood by the client.”

Put simply, it is often stated that whereas the older ‘special state’ interpretation emphasises the difference between hypnosis and ordinary psychological processes, the ‘nonstate’ interpretation emphasises the similarity, continuity, or overlap. In practical terms, nonstate theorists tend to see more of an overlap between hypnotherapy and other forms of psychological therapy, insofar as they employ mental imagery, verbal suggestion, etc., whereas state theorists tend to see hypnotherapy as operating by means of an altered state of consciousness not emphasised in most other psychological therapies.

Comparisons between hypnotised and non-hypnotised subjects suggest that if ‘hypnotic trance’ does exist it probably only accounts for a very small proportion of the effects normally attributed to hypnotic suggestion, most of which can be replicated without the use of a hypnotic induction technique.

Hyper-suggestibility

Braid can be taken to imply, in some of his later writings, that hypnosis is largely a state of heightened suggestibility induced by habit, expectation, and focused attention. In particular, Hippolyte Bernheim became known as the leading proponent of the ‘suggestion theory’ of hypnosis, at one point going so far as to declare that there is no hypnosis (as a specific state) only heightened suggestibility. There is a general consensus among most researchers and clinicians that heightened suggestibility is an essential characteristic of hypnosis, although disagreement exists as to whether this depends upon the induction of an altered state of consciousness (‘hypnotic trance’) or ordinary psychological and physiological factors which mediate the effect of suggestion (nonstate theory).

“If a subject after submitting to the hypnotic procedure shows no genuine increase in susceptibility to any suggestions whatever, there seems no point in calling him hypnotised, regardless of how fully and readily he may respond to suggestions of lid-closure and other superficial sleeping behaviour.”

Conditioned inhibition

Ivan Pavlov stated that hypnotic suggestion provided the best example of a conditioned reflex response in human beings, i.e., that responses to suggestions were learned associations triggered by the words used.

Pavlov himself wrote.,

“Speech, on account of the whole preceding life of the adult, is connected up with all the internal and external stimuli which can reach the cortex, signalling all of them and replacing all of them, and therefore it can call forth all those reactions of the organism which are normally determined by the actual stimuli themselves. We can, therefore, regard ‘suggestion’ as the most simple form of a typical reflex in man.”

He also believed that hypnosis was a ‘partial sleep’ by which he meant that by suggestions of sleep a generalised inhibition of cortical functioning could be encouraged to spread throughout certain regions of the brain. He observed that the various degrees of hypnosis did not significantly differ physiologically from the waking state and hypnosis depended on insignificant changes of environmental stimuli. Pavlov also suggested that lower-brain-stem mechanisms were involved in hypnotic conditioning.

Pavlov’s ideas were combined with those of his rival Bekhterev and became the basis of hypnotic psychotherapy in the Soviet Union, as documented in the writings of his follower K.I. Platonov. Soviet theories of hypnotism subsequently influenced the writings of Western behaviourally-oriented hypnotherapists such as Andrew Salter. However, this theory of hypnosis as a specific state of conditioned cortical inhibition has received little subsequent support from researchers in the field of hypnosis.

Neuropsychology

Neurological imaging techniques have essentially failed to provide any evidence of a neurological pattern that can be directly equated with ‘hypnotic trance’, however differences in brain activity have been found in some studies on highly-responsive hypnotic subjects. Moreover, these changes tend to be task-specific and vary depending upon the type of suggestions being given at the time. A recent review by leading experts who examined the laboratory research in this area concludes.,

“Hypnosis is not a unitary state and therefore should show different patterns of EEG activity depending upon the task being experienced. In our evaluation of the literature, enhanced theta is observed during hypnosis when there is task performance or concentrative hypnosis, but not when the highly hypnotisable individuals are passively relaxed, somewhat sleepy and/or more diffuse in their attention.”

Anna Gosline says in a NewScientist.com article.,

“Gruzelier and his colleagues studied brain activity using an FMRI while subjects completed a standard cognitive exercise, called the Stroop Task. The team screened subjects before the study and chose 12 that were highly susceptible to hypnosis and 12 with low susceptibility. They all completed the task in the fMRI under normal conditions and then again under hypnosis. Throughout the study, both groups were consistent in their task results, achieving similar scores regardless of their mental state. During their first task session, before hypnosis, there were no significant differences in brain activity between the groups. But under hypnosis, Gruzelier found that the highly susceptible subjects showed significantly more brain activity in the anterior cingulate gyrus than the weakly susceptible subjects. This area of the brain has been shown to respond to errors and evaluate emotional outcomes. The highly susceptible group also showed much greater brain activity on the left side of the prefrontal cortex than the weakly susceptible group. This is an area involved with higher level cognitive processing and behaviour.”

Dissociation

Pierre Janet originally developed the idea of dissociation of consciousness as a result of his work with hysterical patients. He believed that hypnosis was an example of dissociation, whereby areas of an individual’s behavioural control are split off from ordinary awareness. Hypnosis would remove some control from the conscious mind, and the individual would respond with autonomic, reflexive behaviour. Weitzenhoffer describes hypnosis via this theory as ‘dissociation of awareness’ from the majority of sensory and even strictly neural events taking place.

Neodissociation

Ernest Hilgard, who developed the ‘neodissociation’ theory of hypnotism, hypothesised that hypnosis causes the subjects to divide our consciousness voluntarily. One part responds to the hypnotist while the other retains awareness of reality. When performing experiments, Hilgard made the subjects go into an ice water bath. They did not say anything about the water being cold or feeling pain. Hilgard then asked the subjects to lift their index finger if they felt pain and 70% of the subjects lifted their index finger. This showed that even though the subjects were listening to the suggestive hypnotist they still had some sense of consciousness.

Social role-taking theory

The main theorist who pioneered the influential role-taking theory of hypnotism was Theodore Sarbin. Sarbin argued that hypnotic responses were motivated attempts to fulfil the socially-constructed role of hypnotic subject. This has led to the misconception that hypnotic subjects are simply ‘faking’. However, Sarbin was careful to emphasise that was not what he meant by distinguishing between role-playing, in which there is little subjective identification with the role in question, and role-taking, in which the subject not only acts externally in accord with the role but also subjectively identifies with it to some degree, acting, thinking, and feeling ‘as if’ they are hypnotised. Sarbin drew analogies between role-taking in hypnosis and role-taking in other areas such as method acting, mental illness, and shamanic possession, etc. This interpretation of hypnosis is particularly relevant to understanding stage hypnosis in which there is clearly strong peer pressure to comply with a socially-constructed role by performing accordingly on a theatrical stage.

Hence, social constructionism and role-taking theory of hypnosis suggests that individuals are enacting (as opposed to merely playing) a role and that really there is no such thing as a hypnotic trance. A socially-constructed relationship is built depending on how much rapport has been established between the “hypnotist” and the subject (see Hawthorne Effect, Pygmalion Effect, and Placebo Effect).

Some psychologists, such as Robert Baker and Graham Wagstaff, claim that what we call hypnosis is actually a form of learned social behaviour, a complex hybrid of social compliance, relaxation, and suggestibility that can account for many esoteric behavioural manifestations.

Cognitive-behavioural theory

Barber, Spanos, & Chaves (1974) proposed a nonstate ‘cognitive-behavioural’ theory of hypnosis, similar in some respects to Sarbin’s social role-taking theory and building upon the earlier research of Barber. On this model, hypnosis is explained as an extension of ordinary psychological processes like imagination, relaxation, expectation, social compliance, etc. In particular, Barber argued that responses to hypnotic suggestions were mediated to a large extent by a ‘positive cognitive set’ consisting of positive expectations, attitudes, and motivation. Daniel Araoz subsequently coined the acronym ‘TEAM’ to symbolise the subject’s orientation to hypnosis in terms of ‘trust’, ‘expectation’, ‘attitude’, and ‘motivation’.

Barber et al., noted that similar factors appeared to mediate the response both to hypnotism and to cognitive-behavioural therapy (CBT), in particular systematic desensitisation. Hence, research and clinical practice inspired by their interpretation has led to growing interest in the relationship between hypnotherapy and CBT.

Information theory

An approach loosely based on information theory uses a brain-as-computer model. In adaptive systems, a system may use feedback to increase the signal-to-noise ratio, which may converge towards a steady state. Increasing the signal-to-noise ratio enables messages to be more clearly received from a source. The hypnotist’s object is to use techniques to reduce the interference and increase the receptability of specific messages (suggestions).

Systems theory

Systems theory, in this context, may be regarded as an extension of Braid’s original conceptualisation of hypnosis as involving a process of enhancing or depressing the activity of the nervous system. Systems theory considers the nervous system‘s organisation into interacting subsystems. Hypnotic phenomena thus involve not only increased or decreased activity of particular subsystems, but also their interaction. A central phenomenon in this regard is that of feedback loops, familiar to systems theory, which suggest a mechanism for creating the more extreme hypnotic phenomena.